1. Field of the Invention
The present invention relates to an audio signal mixer for performing cross-fade on two audio signals and mixing these signals.
2. Description of Background Information
Music generally played in discotheques is so-called dance music which is suitable for dancing. However, even with such dance music, it is not preferable to change the tempo every time a different piece of music is played because people may find it difficult to dance to the accompaniment of such tempo-changing music. On the other hand, continuously replaying the same music for a long time, by reason of not changing the tempo, causes the people to lose their interest in the dancing. Thus, disk jockey dedicated to edit pieces of dance music in a discotheque is provided with a plurality of (for example, two) disk players in order to replay a next piece of music (second piece) immediately after the completion of a currently replayed piece of music (first piece) through a mixer for editing. In this event, while the first piece is being replayed by one player, the head of the next piece (second piece) is searched for in the other player and the disk rotating speed of the other player is controlled such that replay of the second piece can be started at the time replay of the first piece has been completed.
As an editing method employed for editing the transition from a first piece of music to a second piece of music, a cut-in editing, a long mix editing, and so on are performed depending on the taste of individual disk jockeys. Among these mixing techniques, the long mix editing is such an editing that mixes the first piece with the second piece using a mixer for cross-fading the first and second pieces. However, the long mix editing requires a disk jockey to perform complicated operations on two disk players and on a mixer. Specifically, the disk jockey, after searching for the head of a second piece, maintains the second piece ready for starting the replay at any time, and when an editing point of the first piece has reached to start cross-fade, the disk jockey must start the replay of the second piece while performing a cross-fade adjustment.
It is therefore an object of the present invention to provide an audio signal mixer which is capable of achieving the long mix editing with simple manipulations.
The audio signal mixer according to the present invention is characterized by first audio signal producing apparatus for producing a first audio signal, second audio signal producing apparatus for producing a second audio signal, a single operating member movable between a first end and a second end, level adjusting means for progressively decreasing the level of the first audio signal as the operating member is positioned closer to the second end and for progressively decreasing the level of the second audio signal as the operating member is positioned closer to the first end, means for adding the first and second audio signals which have their levels adjusted by the level adjusting means, means for detecting the position of the operating member, and control means for stopping a producing operation of the second audio signal by the second audio signal producing means when the operating member is positioned at the first end and for stopping the producing operation of the first audio signal by the first audio signal producing means when the operating member is positioned at the second end.
According to the present invention, the second audio signal producing means is prevented from producing a second audio signal when the operating member is positioned at the first end. When the operating member is moved away from the first end, the second audio signal is produced and mixed with a first audio signal. As the operating member is moved toward the second end, the level of the first audio signal is gradually decreased, while the level of the second audio signal is gradually increased. When the operating member has reached the second end, the first audio signal generating means is prevented from producing the first audio signal. Conversely, when the operating member is moved away from the second end, the first audio signal is produced and mixed with the second audio signal. As the operating member is moved toward the first end, the level of the second audio signal is gradually decreased, while the level of the first audio signal is gradually increased. When the operating member has reached the first end, the second audio signal producing means is prevented from producing the second audio signal.